DirecTV is saying its customers were left without Nickelodeon, MTV, Comedy Central and 14 other channels on Wednesday after Viacom Inc. demanded that its networks be dropped from DirectTV's lineup in a dispute over fees.

DirecTV, the largest U.S. satellite TV provider with nearly 20 million subscribers, said its executives had approached Viacom with a new proposal and a request to continue broadcasting the channels as talks proceeded, but received no response.

DirecTV's contract with Viacom, which had been in place for the last seven years, expired at midnight Tuesday.